Understanding Amazon CloudSearch Limits

This table shows naming and size restrictions within Amazon CloudSearch. You can submit a request if you need to increase the maximum number of search instances or partitions for a search domain. For information about increasing other limits such as the maximum number of search domains, contact Amazon CloudSearch.

The current Amazon CloudSearch limits are summarized in the following table.

Item

Limit

Batch size

The maximum batch size is 5 MB.

Document size

The maximum document size is 1 MB.

Expressions

Up to 50 expressions can be configured for a domain.

The maximum
size of an expression is 10240 bytes.

The maximum value that can be
returned by an expression is max(int64_t).

Highlighting

The maximum number of occurrences of the search term(s) that can be highlighted is 5.

Highlights are only returned for the first 10 KB of data in a text field.

Index fields

Up to 200 index fields can be configured for a domain.

Up to 1000 values can be specified in a field.

Up to 20 sources can be specified for an array-type field.

The maximum size of a literal field is 4096 UTF-8 code points.

The maximum size of a default value for a field is 1 KB.

An int field can contain values from
-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
(inclusive).

Individual terms within a text or text-array field are treated as stopwords if they exceed 256 characters.

Naming conventions

Domain Names: Allowed characters are a-z (lower-case letters), 0-9, and hyphen (-). Domain names must start with a letter or number and be at least 3 and no more than 28 characters long.

Field Names: Allowed characters are a-z (lower-case letters), 0-9, and _ (underscore). Field names must begin with a letter and be at least 1 and no more than 64 characters long. The name score is reserved and cannot be used as a field name.

Expression Names: Allowed characters are a-z (lower-case letters), 0-9, and _ (underscore). Expression names must begin with a letter and be at least 3 and no more than 64 characters long. The name score is reserved and cannot be used as an expression name.

Document IDs: A document ID (_id) can contain any letter or number and the following characters: _ - = # ; : / ? @ &. Document IDs must be at least 1 and no more than 128 characters long.

Policy document size

The maximum size of an Amazon CloudSearch policy document is 100 KB.

_score

A document's text relevance score is a positive floating point
value.

Search domains

Each AWS account can create up to 100 search domains.

Search instances

The maximum number of search instances that can be deployed for a domain is 50.